The burning rates of solid propellant compositions have been the subject of much research and development work. These research and development works have demonstrated in the field of solid propellants that the burning rates of solid propellant compositions are higher as the particle size of the oxidizer is decreased, especially for the ammonium perchlorate oxidized systems. This relationship of burning rate to particle size of oxidizer has been demonstrated in all the binder systems used (double-base, polyurethanes, polyesters, rubbers, etc.).
To achieve a reduction of ammonium perchlorate (AP) particle size to the ultra-fine state (e.g. less than 2.5 micron average particle size) and to the ultra-ultra-fine state (e.g. less than 0.5 micron average particle size) special grinding aids have been developed for the function of preventing agglomeration of the extremely fine AP during grinding and in propellant mixing procedures. Other problems have been associated with using ultra-ultra-fine AP. One problem has been maintaining consistency of burning rate in propellants where the AP has been from different production batches. Also, the cost increase of ultra-ultra-fine AP and the resulting cost increase of the propellant composition is significant due to increased power requirements due to grinding and mixing. The pot life of ultra-ultra-fine AP oxidized propellants is shortened without the use of pot life extenders such as aziridine compounds (e.g. N-phenethylaziridine and other selected alkyl diaziridine compounds). The problems associated with loss of pot life have resulted not only in increased cost but in variable quality and performance for the finished propellant grain.
An object of this invention is to provide a propellant composition with improved burning rate as a result of an improved method of dispersing the oxidizer for the propellant composition.
Another object of this invention is to provide a soluble oxidizer for employment in a propellant mixing procedure which results in an intimate dispersion of the oxidizer in the finished propellant composition.